T
Tamping
Compacting the ballast beneath the ties to provide a consistent, level surface.
Tangent
Any straight portion of a railway alignment.
Theoretical point
The point of intersection of the gage lines of a frog.
Thermit Weld
A form of cast weld used to join two rails at the ends.
Throat of Frog
The point at which the converging wings of a frog are closest together.
Throw of Switch
The distance through which the switch points are moved from open to closed measured along the center line of the No. 1 switch rod or head rod.
Tie Plate
A plate installed between a rail and a tie.
Toe End of Frog
The end of a frog which is nearer to the switch or the end which has both gage lines between the wing rails or other running surfaces.
Toe Length
The distance between the toe end and the half-inch point of a frog, measured along the gage line.
Toe Spread
The distance between the gage lines at the toe end of the frog.
Track
An assembly of rails, ties and fastenings over which cars, locomotives and trains are moved.
Track Bolt
A bolt with a button head and oval or diamond neck and a threaded nut designed to fasten together rails and joint bars.
Trail
Run through a switch without damaging it.
Transverse Defect
For defects found by detector cars a tentative group classification, applied prior to the breaking of the rails, of all types of rail defects which have transverse components such as transverse fissures, compound fissures and detail fractures.
Transverse Fissure
A progressive crosswise fracture starting from a crystalline center or nucleus inside the head from which it spreads outward as a smooth, bright or dark, round or oval surface substantially at a right angle to the length of the rail. The distinguishing features of a transverse fissure from other types of fractures or defects are the crystalline center or nucleus and the nearly smooth surface of the development which surrounds it.
Turnout
An arrangement of a switch and a frog with closure rails by means of which rolling stock may be diverted from one track to another.
Turnout Number
The number corresponding to the number of the frog used in the turnout.
Compacting the ballast beneath the ties to provide a consistent, level surface.
Tangent
Any straight portion of a railway alignment.
Theoretical point
The point of intersection of the gage lines of a frog.
Thermit Weld
A form of cast weld used to join two rails at the ends.
Throat of Frog
The point at which the converging wings of a frog are closest together.
Throw of Switch
The distance through which the switch points are moved from open to closed measured along the center line of the No. 1 switch rod or head rod.
Tie Plate
A plate installed between a rail and a tie.
Toe End of Frog
The end of a frog which is nearer to the switch or the end which has both gage lines between the wing rails or other running surfaces.
Toe Length
The distance between the toe end and the half-inch point of a frog, measured along the gage line.
Toe Spread
The distance between the gage lines at the toe end of the frog.
Track
An assembly of rails, ties and fastenings over which cars, locomotives and trains are moved.
Track Bolt
A bolt with a button head and oval or diamond neck and a threaded nut designed to fasten together rails and joint bars.
Trail
Run through a switch without damaging it.
Transverse Defect
For defects found by detector cars a tentative group classification, applied prior to the breaking of the rails, of all types of rail defects which have transverse components such as transverse fissures, compound fissures and detail fractures.
Transverse Fissure
A progressive crosswise fracture starting from a crystalline center or nucleus inside the head from which it spreads outward as a smooth, bright or dark, round or oval surface substantially at a right angle to the length of the rail. The distinguishing features of a transverse fissure from other types of fractures or defects are the crystalline center or nucleus and the nearly smooth surface of the development which surrounds it.
Turnout
An arrangement of a switch and a frog with closure rails by means of which rolling stock may be diverted from one track to another.
Turnout Number
The number corresponding to the number of the frog used in the turnout.
